qrupdate: fix darwin

with the sdk refactor cmake will use Accelerate for the blas/lapack
libs. Unfortunately, this breaks qrupdate and causes all test to fail,
most of them by segfaulting. Set the Blas vendor to Generic to prevent
cmake from using Accelerate and use the nixpkgs provided blas/lapack
libraries

pkgs/development/libraries/qrupdate/default.nix

@@ -28,6 +28,9 @@ stdenv.mkDerivation (finalAttrs: {
       # https://savannah.gnu.org/bugs/?50339
       "-fdefault-integer-8"
     ])}"
+  ] ++ lib.optionals stdenv.hostPlatform.isDarwin [
+    # prevent cmake from using Accelerate, which causes all tests to segfault
+    "-DBLA_VENDOR=Generic"
   ];
 
   # https://github.com/mpimd-csc/qrupdate-ng/issues/4